With regard to this kind of device or apparatus, a technique utilizing multi-scale recognition is known. This technique includes calculating a set of traffic lines of a subject vehicle and an obstacle, estimating a risk in each traffic line based on existing probabilities of the subject vehicle and the obstacle at a point of intersection of their routes, and selecting a driving action (see Japanese Application Publication No. JP2011-96105A).
In the above prior art, however, a number of traffic lines of the subject vehicle and the obstacle are created as the traffic lines are subdivided by the multi-scale recognition, so the number of processing objects will be considerably large and, unfortunately, it may be difficult to determine the driving action in real time.
A problem to be solved by the present invention is to provide a drive planning device that quickly determines a driving operation plan in accordance with a scene which a subject vehicle traveling on a route encounters.